This invention relates to a method for improving the combustion efficiency of gasoline fuel in the internal combustion engine mounted on an automobile, particularly to such a method which is characterized by adding ammonia gas, which can be produced from any desired ammonia compounds such as liquid ammonia or ammonium carbonate, to the gaseous or mist form of gasoline to be incorporated into the engine, whereby the combustion efficiency of the engine is enhanced while the amounts of pollutants contained in the discharged gas are minimized.
Conventionally, for decreasing the amount of pollutants contained in the gas discharged from the internal combustion engine, several methods have been developed and used on a trial basis including a group of methods which have treated the discharged gas after combustion and a group of methods which have added some additives to the hydrocarbon fuel prior to the combustion in the engine.
In the latter group of methods, although they have worked effectively in some particular conditions or cases, most of them have incurred a decrease in combustion efficiency.
As a fuel additive composition which can decrease the amount of pollutants in the discharged gas while keeping a high combustion efficiency, a composition which comprises a major amount of white oil, 1 to 4 percent by volume, based on the total volume of composition and about 0.02 to 0.1 percent by volume, based on the total volume of the composition of oil of orange is disclosed in U.S. Pat. No. 3,820,962 (patented on June 28, 1974).
Meanwhile, for obtaining the complete combustion of fuel in the internal combustion engine, methods which inject a reforming agent into the gasoline vapor have been developed wherein a method which injects the water vapor into the intake manifold of the internal combustion engine or a method which injects the alcohols, the mixture of water and alcohol, or the mixture of water, alcohol, propylene and acetone have been well known. It is believed that the addition of water vapor or alcohol enhances combustion and produces a discharged gas of favorable composition.
Although alcohol which contains oxygen facilitates the complete combustion as has been described above, lower alcohol such as methanol requires a delicate technique in mounting the supply device thereof and causes the methanol residue by thermal decomposition which is troublesome in disposal. Furthermore, the alcohol does not have compatibility with hydrocarbon.
Meanwhile, the oxygen-containing alcohol has a tendency to produce nitrogen oxide at high temperatures of more than 1200.degree. C. while it causes incomplete combustion at low temperatures. Accordingly, in the above method a compound is employed besides alcohol for providing complete combustion without producing nitrogen oxide. Also, started from the same technical idea is a method which adds acetate, a mixture of acetate and alcohol, or a mixture of the above components with water into the fuel before combustion. In the above method, when the fuel is in a gaseous form, the above additive is incorporated into the fuel in a mist form prior to the mixture of fuel and air. When the fuel is in a liquid form, the additive is dissolved in the fuel beforehand (Japanese patent laid open publication SH049-44006).
The methods discussed above have employed the compound composed of hydrocarbon and oxygen for obtaining complete combustion of hydrocarbon fuel.
Meanwhile, a method which uses a compound containing nitrogen as a fuel additive is known. When the operators of racing cars want extra performance for limited periods of time, they add 5 percent nitro-methane to the methanol in the fuel tank. It has also been reported that combustion is increased by mixing gasoline, benzene and methanol. In conjunction with the above method, U.S. Pat. No. 3,807,972 (granted on Apr. 30, 1974) discloses a method for improving the combustion efficiency wherein the mixture consisting of 75 percent methanol, 5 percent nitro-methane, 2 percent nitro-benzene and 18 percent acetone is mixed with water and the thus produced mixture is vaporized. Subsequently the vaporized mixture is injected into the intake manifold of the internal combustion engine, whereby the combustion performance of the engine is enhanced while the composition of the discharged gas is improved.
The inventor of this invention also has continued a study on the method for enhancing the combustion efficiency of the fuel in the internal combustion engine and has unexpectedly found that when the ammonia gas, produced from a compound which can produce such ammonia gas, is mixed with the intake air and subsequently is slightly mixed with the gaseous or mist form of gasoline to be charged into the internal combustion engine, the output of the engine is greatly enhanced resulting in a reduced consumption of fuel.
The applicant also has found that addition of such mixture into the fuel can improve the combustion efficient without substantially increasing the adverse nitrogen oxide content within the discharged gas.
Accordingly, it is an object of the present invention to provide a method for improving the combustion efficiency of hydrocarbon fuel within the combustion chamber of the internal combustion engine which is characterized by the addition of ammonia gas or a volatile ammonium compound to the gaseous or mist form of gasoline in the fuel stream of the internal combustion engine.
It is another object of the present invention to provide such a method for improving the combustion efficiency while decreasing the amount of pollutants within the discharged gas.
It is a further object of the present invention to provide a device applicable to the method of this invention which can continuously add the ammonia gas produced from ammonium compound to the hydrocarbon fuel in the internal combustion engine.
It is a still further object of the present invention to provide such a device which is of a simple and yet rigid construction so that it can be easily installed in an automobile of any desired type.
These and other objects of the invention will be seen by reference to the following description, taken in connection with the accompanying drawings.